Difficulty with basic tasks such as walking a short distance or basic activities of daily living (ADL) rises rapidly with age and becomes common in old age. These disabilities have detrimental effects on quality of life in older people, and are risk factors for other adverse outcomes including death and nursing home use. Most disability in the elderly develops insidiously from the long term interaction of many risk factors. Musculoskeletal conditions such as arthritis and back pain are important mediators of disability. However, few studies have used long periods of follow-up to examine the impact of mid-life musculoskeletal conditions on later life disability. Doing so is important because the impact of these conditions on disabilty is likely slow and progressive. As a result, the full impact of these conditions on disability in the elderly is likely to be underestimated unless observation begins before the onset of old age, and continues for long time periods. We propose to make innovative use of the population-based Health and Retirement Study (HRS) to examine the impact of self-reported mid-life musculoskeletal conditions (arthritis and back pain) on later life disability (walking difficulty and difficulty with ADL). We will follow 9759 subjects who were age 51-61 when enrolled in 1992 and will range in age from 67-77 by 2008. At baseline, subjects reported the presence of symptomatic arthritis and back pain. At each 2-year follow-up subjects report whether they have difficulty with basic activities of daily living (bathing, dressing, transferring, toileting, and eating) and with mobility (walking various distances and up stairs). We plan a comprehensive series of aims that will determine the impact of mid-life musculoskeletal conditions on later life disability, the impact of other demographic characteristics and comorbid conditions on these relationships, and the impact of arthritis and back pain on other outcomes closely related to disabilty including death, nursing home use, caregiver burden, and retirement. Our aims are to: (1)examine the impact of self-reported symptomatic arthritis in mid-life on later life disability, including difficulty performing basic activities of daily living and mobility difficulties;(2)examine the impact of back pain in mid-life on later life disability;(3)examine whether the impact of arthritis and back pain on disability differs in demographic groups defined by race, gender, and socio-economic status;(4) examine whether the impact of arthritis and back pain on disability differs depending on the presence of other comorbid medical conditions, obesity, and depression;(5)examine whether arthritis and back pain are associated with outcomes that are common consequences of disability such as caregiver burden, nursing home placement, and death;(6)determine whether arthritis and back pain are associated with early retirement and whether early retirement identifies a subset of subjects with arthritis and back pain at particularly high risk for subsequent disability.